About 70 adolescents between ages 13 and 19 sought treatment in an emergency room or called the Oregon Poison Center over symptoms such as anxiety, agitation and hallucinations. That compares with 40 the year before.

The rise is worrisome, but not alarming, said Dr. Robert Hendrickson, associate medical director of the poison center, located at Oregon Health & Science University.

"I think you can look at it two ways," he said. "It's increasing and that is a concern. On the other hand, 70 cases for the entire state in a whole year is pretty small."

Though the emergency cases are up, marijuana use among Oregon adolescents has remained flat over the past five years, according to state health officials. A report published last week noted a slight increase in use of cannabis by teens nationwide in 2017.

The Oregon Poison Center's data stem from calls from emergency rooms across the state. They also include some calls by individuals seeking advice.

There's no antidote for marijuana poisoning. You just have to wait it out. In severe cases, patients must be put on a ventilator and kept in the hospital for perhaps a day or two. That was not not case with any of the teens in the past two years.

"Most people who we get a call about do well," Hendrickson said. "Their symptoms last for a couple of hours and then they get better and go home."

The symptoms go away as the marijuana is flushed out of the bloodstream.

Oregon has had at least two cases involving children between 1 and 2 years old who consumed cannabis and experienced severe symptoms. One within the past two years stopped breathing, Hendrickson said, and had to be put on a ventilator.

There have been no deaths in Oregon attributed to marijuana, Hendrickson said.